"""Pure-NumPy overlay geometry for Finger 3D arrows."""

from __future__ import annotations

import numpy as np
import pytest
from orisys_app_shared.scene3d.overlays import (
    arrow_instances_to_mesh,
    build_flow_overlay,
    build_normal_overlay,
    force_visual_strength,
)
from orisys_app_shared.scene3d.synthetic import poc_scene
from orisys_app_shared.scene3d.visual_policy import FlowSamples, VisualPolicy, select_flow_samples


def test_force_visual_strength_is_capped() -> None:
    assert force_visual_strength(0.0) == 0.0
    strong = force_visual_strength(1e9)
    mild = force_visual_strength(100.0)
    assert strong >= mild > 0.0
    assert strong <= 1.0 + 1e-9


def test_flow_and_normal_overlays_on_poc_mapping() -> None:
    assets = poc_scene()
    mapping = assets.surface_mapping
    assert mapping is not None
    h, w = mapping.shape_hw
    flow = np.zeros((h, w, 2), dtype=np.float64)
    flow[1, 1] = (0.8, 0.0)
    mask = np.asarray(mapping.valid, dtype=bool)
    policy = VisualPolicy(
        flow_on_px=0.4,
        flow_grid_spacing=1,
        flow_edge_margin=0,
        max_arrows=50,
    )
    samples = select_flow_samples(flow, mask, policy)
    arrows, diags = build_flow_overlay(samples, mapping, style=policy)
    assert not diags
    assert arrows is not None and arrows.origins.shape[0] >= 1
    contact, cdiags = build_normal_overlay(
        contact_uv_xy=(1.0, 1.0),
        contact_found=True,
        contact_valid=True,
        fn=500.0,
        mapping=mapping,
    )
    assert not cdiags
    assert contact is not None and contact.origins.shape[0] == 1
    # Yellow-ish contact colour.
    assert float(contact.colors[0, 0]) > 0.7
    assert float(contact.colors[0, 1]) > 0.7

    positions, triangles, colors = arrow_instances_to_mesh(arrows)
    assert positions.ndim == 2 and positions.shape[1] == 3
    assert triangles.ndim == 2 and triangles.shape[1] == 3
    assert colors.shape[0] == positions.shape[0]


def test_an_inactive_sample_is_a_grey_point_and_an_active_one_is_an_arrow() -> None:
    assets = poc_scene()
    mapping = assets.surface_mapping
    assert mapping is not None
    samples = FlowSamples(
        rows=np.asarray([1, 1], dtype=np.int32),
        cols=np.asarray([1, 2], dtype=np.int32),
        dx=np.asarray([0.8, 0.0]),
        dy=np.asarray([0.0, 0.0]),
        magnitude=np.asarray([1.6, 0.0]),
        active=np.asarray([True, False]),
    )
    arrows, diags = build_flow_overlay(samples, mapping)
    assert not diags
    assert int(np.count_nonzero(arrows.lengths > 0.0)) == 1
    assert int(np.count_nonzero(arrows.lengths < 0.0)) == 1
    idle = arrows.colors[arrows.lengths < 0.0][0]
    # Brand idle tint #8A93A6, not a ramp colour.
    assert idle[0] == pytest.approx(0x8A / 255.0, abs=0.02)
    assert idle[2] == pytest.approx(0xA6 / 255.0, abs=0.02)
    positions, _triangles, colors = arrow_instances_to_mesh(arrows)
    assert positions.shape[0] == colors.shape[0] > 0


def test_missing_contact_yields_no_arrow() -> None:
    assets = poc_scene()
    mapping = assets.surface_mapping
    assert mapping is not None
    arrows, _ = build_normal_overlay(
        contact_uv_xy=(1.0, 1.0),
        contact_found=False,
        contact_valid=True,
        fn=100.0,
        mapping=mapping,
    )
    assert arrows.origins.shape[0] == 0